CCD imaging device and driving method thereof

ABSTRACT

One horizontal CCD register is provided for a plurality of vertical CCD registers. The horizontal CCD register has horizontal transfer electrodes in such a manner that transfer electrodes that are provided for each pair of vertical CCD registers adjacent to each other are independent of each other electrically. The eight transfer electrodes are supplied with eight kinds of horizontal transfer pulse signals, respectively. An operation that the horizontal CCD register consecutively outputs consecutive signal charges in the same manner as in the conventional two-phase driving method and an operation that the horizontal CCD register outputs consecutive signal charges while mixing desired ones are performed selectively by controlling the eight kinds of horizontal transfer pulse signals properly.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.application Ser. No. 10/060,544, filed Jan. 30, 2002, now U.S. Pat No.6,970,197, and also claims priority to Japanese Application No.P2001-029020, filed Feb. 6, 2001, which applications are incorporatedherein by reference to the extent permitted by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a solid-state imaging device having aplurality of photodetecting portions that are arranged two-dimensionallyand vertical CCD registers and a horizontal CCD register(s) fortransferring signal charges that are output from the photodetectingportions, as well as to a driving method of such a solid-state imagingdevice.

2. Description of the Related Art

Among conventional CCD imaging devices of the above kind is known onehaving a horizontal CCD register shown in FIGS. 1A and 1B and FIGS.2A-2E.

In the CCD imaging device shown in FIG. 1A, one horizontal CCD register20 is provided for a plurality of vertical CCD registers 10 on thehorizontal CCD register 20. Two-layer transfer electrodes 30A and 30Bare provided in two pairs for each vertical CCD register 10 on thehorizontal CCD register 20. Two-phase horizontal drive pulse signals H1and H2 having opposite polarities are applied alternately to the pairsof transfer electrodes 30A and 30B.

As shown in FIG. 1B, the charge transfer region of the horizontal CCDregister 20 is so formed as to have prescribed potential differencesthat correspond to the respective transfer electrodes 30A and 30B.

Therefore, by applying the horizontal drive pulse signals H1 and H2 tothe transfer electrodes 30A and 30B corresponding to each pair ofvertical CCD registers 10 adjacent to each other as shown in FIGS. 2Aand 2E, a signal charge transfer operation is performed in such a mannerthat the potentials of the charge transfer region of the horizontal CCDregister 20 are controlled sequentially as shown in FIGS. 2B-2D.

That is, a two-phase-drive CCD, in which phase control can be performedrelatively easily, is employed as the horizontal CCD register 20 thattransfers signal charges at high speed.

FIGS. 3A-3F show another conventional CCD imaging device in which twohorizontal CCD registers are provided for a plurality of vertical CCDregisters.

Specifically, in the CCD imaging device shown in FIG. 3A, two horizontalCCD registers 50 and 60 are provided for a plurality of vertical CCDregisters 40. The two horizontal CCD registers 50 and 60 share handlingof signal charges that are output from the respective vertical CCDregisters 40 and perform transfer operations parallel. Signal chargesthat are transferred by the horizontal CCD registers 50 and 60 areoutput to a charge detecting section (not shown) via a final gatesection 70.

Also in this CCD imaging device, in each of the horizontal CCD registers50 and 60, two-layer transfer electrodes 80A and 80B are provided in twopairs for each vertical CCD register 40. Two-phase horizontal drivepulse signals H1 and H2 having opposite polarities are appliedalternately to the pairs of transfer electrodes 80A and 80B. Signalcharges are transferred by the same operation as in the CCD imagingdevice of FIG. 1A and merge together in the final gate section 70.

Incidentally, in image sensors using the above conventional CCD imagingdevices, the signal output rate should be increased as the number ofpixels increases if the number of frames per unit time is kept constant.Actually, however, the output rate can not necessarily be increasedeasily when other factors such as the power consumption are taken intoconsideration.

On the other hand, when the output rate is not increased, the number offrames per unit time should necessarily be decreased, which meansdecrease in the amount of information relating to motion.

In still cameras, for example, it is necessary to bring the camera intofocus and determine exposure by monitoring images in addition to takeimages to be recorded actually. For merely monitoring images, it is moreimportant to secure a sufficient number of frames per unit time thanobtaining high-resolution images.

In view of the above, a conventional technique is employed that thenumber of pixels used is decreased by decimating pixels and the numberof images per unit time is thereby increased.

Among methods for decimating pixels are a method that read operationsthemselves on the photodetecting portions are decimated and a methodthat the number of signal charge packets is decreased by mixing signalcharges adjacent to each other.

Pixels can be decimated in the vertical direction by prohibiting readingfrom part of the photodetecting portions through control by the readgate. However, it is difficult to perform reading for only arbitrarypixels in the horizontal direction because the electrodes are arrangedcontinuously in the horizontal direction.

Therefore, in the horizontal direction, the method that signal chargesare mixed with each other remains a candidate. However, the number oftransfer stages is fixed in ordinary structure horizontal CCD registersas shown in FIG. 1A. This results in a problem that the drive frequencycannot be decreased in accordance with a decreased number of signalcharge packets and hence the frame rate cannot be increased.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstancesin the art, and an object of the invention is therefore to provide a CCDimaging device capable of outputting, in a horizontal CCD register,signal charges that are consecutive in the horizontal direction whilemixing desired signal charges and hence capable of increasing the framerate without increasing the drive frequency, as well as a driving methodof such a CCD imaging device.

The invention provides a CCD imaging device comprising a plurality ofphotodetecting portions that are arranged two-dimensionally; a pluralityof vertical CCD registers for transferring, in a vertical direction,signal charges that are output from the respective photodetectingportions; and a single horizontal CCD register for transferring, in ahorizontal transfer direction, signal charges that have been transferredby the vertical CCD registers, the horizontal CCD register havinghorizontal transfer electrodes in such a manner that four transferelectrodes that are provided so as to correspond to each of the verticalCCD registers are independent of each other electrically.

In this imaging device having the single horizontal CCD register, thehorizontal CCD register has horizontal transfer electrodes in such amanner that four transfer electrodes that are provided so as tocorrespond to each vertical CCD register are independent of each otherelectrically. Therefore, the horizontal transfer of signal charges canbe performed by driving the four transfer electrodes independently byarbitrary horizontal transfer pulse signals.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

The invention also provides a CCD imaging device comprising a pluralityof photodetecting portions that are arranged two-dimensionally; aplurality of vertical CCD registers for transferring, in a verticaldirection, signal charges that are output from the respectivephotodetecting portions; and m horizontal CCD registers fortransferring, in a horizontal transfer direction, signal charges thathave been transferred by the vertical CCD registers, the m horizontalCCD registers having horizontal transfer electrodes in such a mannerthat all of transfer electrodes that are provided so as to correspond toeach of the vertical CCD registers are independent of each otherelectrically.

In this imaging device having the m horizontal CCD registers, the mhorizontal CCD registers have horizontal transfer electrodes in such amanner that all of transfer electrodes that are provided so as tocorrespond to each vertical CCD register are independent of each otherelectrically. Therefore, the horizontal transfer of signal charges canbe performed by driving the transfer electrodes independently byarbitrary horizontal transfer pulse signals.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

The invention provides a driving method of a CCD imaging devicecomprising a plurality of photodetecting portions that are arrangedtwo-dimensionally, a plurality of vertical CCD registers fortransferring, in a vertical direction, signal charges that are outputfrom the respective photodetecting portions, and a single horizontal CCDregister for transferring, in a horizontal transfer direction, signalcharges that have been transferred by the vertical CCD registers,wherein the horizontal CCD register has horizontal transfer electrodesin such a manner that four transfer electrodes that are provided so asto correspond to each of the vertical CCD registers are independent ofeach other electrically; and wherein the four transfer electrodes aredriven by independent drive pulse signals.

In this driving method of the CCD imaging device having the singlehorizontal CCD register, the horizontal CCD register has horizontaltransfer electrodes in such a manner that four transfer electrodes thatare provided so as to correspond to each of the vertical CCD registersare independent of each other electrically, and the horizontal transferof signal charges is performed by driving the four transfer electrodesindependently by arbitrary horizontal transfer pulse signals.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

The invention also provides a driving method of a CCD imaging devicecomprising a plurality of photodetecting portions that are arrangedtwo-dimensionally, a plurality of vertical CCD registers fortransferring, in a vertical direction, signal charges that are outputfrom the respective photodetecting portions, and m horizontal CCDregisters for transferring, in a horizontal transfer direction, signalcharges that have been transferred by the vertical CCD registers,wherein the m horizontal CCD registers have horizontal transferelectrodes in such a manner that all of transfer electrodes that areprovided so as to correspond to each of the vertical CCD registers areindependent of each other electrically; and wherein the transferelectrodes corresponding to each of the vertical CCD registers aredriven by independent drive pulse signals.

In this driving method of the CCD imaging device having the m horizontalCCD registers, the m horizontal CCD register have horizontal transferelectrodes in such a manner that all of transfer electrodes that areprovided so as to correspond to each of the vertical CCD registers areindependent of each other electrically, and the horizontal transfer ofsignal charges is performed by driving the transfer electrodesindependently by arbitrary horizontal transfer pulse signals.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are a schematic plan view and a potential diagram of ahorizontal CCD register of a conventional CCD imaging device;

FIGS. 2A-2E are explanatory diagrams showing a driving method of theconventional CCD imaging device of FIGS. 1A and 1B;

FIGS. 3A-3F are a schematic plan view and explanatory diagrams showing ahorizontal CCD register of another conventional CCD imaging device and adriving method thereof;

FIG. 4 is a schematic plan view of an interline transfer CCD imagingdevice according to a first embodiment of the invention;

FIG. 5 is a schematic plan view of a horizontal CCD register of the CCDimaging device of FIG. 4.

FIGS. 6A-6E show an exemplary operation in a case that the CCD imagingdevice of FIG. 4 outputs signal charges consecutively in the same manneras in a conventional two-phase driving method;

FIGS. 7A-7C show a first exemplary operation in a case that the CCDimaging device of FIG. 4 outputs signal charges that are arranged in thehorizontal direction while mixing desired ones;

FIGS. 8A-8C show a second exemplary operation in the case that the CCDimaging device of FIG. 4 outputs signal charges that are arranged in thehorizontal direction while mixing desired ones; and

FIG. 9 is a schematic plan view of a horizontal CCD register of a CCDimaging device according to a second embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

CCD imaging devices and driving methods thereof according to embodimentsof the present invention will be hereinafter described.

Preferred embodiments will be described below. Although the embodimentswill include various technically preferable limitations, the scope ofthe invention is not restricted to those limitations unless a statementto the contrary is made.

FIG. 4 shows an interline transfer (IT) CCD imaging device according toa first embodiment of the invention. As shown in FIG. 4, a plurality ofphotodetecting portions 100 each for converting incident light into asignal charge of an amount corresponding to the quantity of the incidentlight are arranged two-dimensionally. A vertical CCD register 110 isprovided for each vertical column of photodetecting portions 100.Reference numeral 115 denotes a unit cell. Signal charges that have beenread from photodetecting portions 100 are transferred in order in thevertical direction while being shifted in part of each horizontalblanking period.

Signal charges that have been transferred in the vertical direction bythe vertical CCD registers 110 are moved to a horizontal CCD register120 in order line by line. The horizontal CCD register 120 transfersone-line signal charges in order in the horizontal direction in ahorizontal scanning period that follows each horizontal blanking period.The signal charges that have been transferred in the horizontaldirection by the horizontal CCD register 120 are converted into signalvoltages at the transfer destination end and then output via an outputsection 108 that is a source follower circuit or the like.

FIG. 5 is a schematic plan view of a horizontal CCD register of the CCDimaging device of FIG. 4.

In the CCD imaging device of FIG. 4, the one horizontal CCD register 120is provided for a plurality of vertical CCD registers 110. In thehorizontal CCD register 120, eight horizontal transfer electrodes131-138 that are independent of each other electrically are provided foreach pair of vertical CCD registers 110 adjacent to each other. Eightkinds of horizontal pulse signals H11-H18 are applied to the respectivetransfer electrodes 131-138.

In this embodiment, by controlling the respective horizontal transferpulse signals H11-H18 in a driving method as described below, anoperation that the horizontal CCD register 120 consecutively outputsconsecutive signal charges in the same manner as in the conventionaltwo-phase driving method and an operation that the horizontal CCDregister 120 outputs consecutive signal charges while mixing desiredones can be performed selectively.

Next, a driving method of the above CCD imaging device will bedescribed.

FIGS. 6A-6E show an exemplary operation of the above CCD imaging devicethat signal charges are output consecutively in the same manner as inthe conventional two-phase driving method.

Most of the conventional horizontal CCD registers employ the two-phasedriving method in which the phases can be managed relatively easily. Asdescribed in the above conventional example (see FIGS. 1A and 1B), eachpair of transfer electrodes adjacent to each other to which the samedriving pulse signal is applied have a prescribed potential difference.

In the horizontal CCD register 120 of this embodiment, among the eighthorizontal transfer pulse signals H11-H18, two that are applied to eachpair of transfer electrodes adjacent to each other are given a voltagedifference, whereby a horizontal transfer operation can be obtained thatbehaves as if it were the horizontal transfer operation of theconventional two-phase driving method.

More specifically, as shown in FIG. 6E two pairs of horizontal transferpulse signals H11, H12, H15, and H16 are in phase. The other two pairsof horizontal transfer pulse signals H13, H14, H17, and H18 are in phaseand are opposite in polarity to the horizontal transfer pulse signalsH11, H12, H15, and H16. A voltage difference a is provided between theeven-numbered horizontal transfer pulse signals H12, H14, H16, and H18and the odd-numbered horizontal transfer pulse signals H11, H13, H15,and H17, respectively.

Signal charges are transferred by controlling the potential of thecharge transfer region of the horizontal CCD register 120 in order asshown in FIGS. 6B-6D by applying such horizontal transfer pulse signalsH11-H18 to the respective transfer electrodes 131-138. In this manner,the horizontal CCD register 120 can be used completely in the samemanner as the conventional two-phase horizontal CCD register.

FIGS. 7A-7C show a first exemplary operation of the case that the CCDimaging device outputs signal charges arranged in the horizontaldirection while mixing desired ones.

Two transfer electrodes adjacent to each other are considered a pair andthe eight transfer electrodes 131-138 are driven in four phases. Thehorizontal transfer pulse signals H11 to H18 are controlled as to havephase relationships shown in FIG. 7C.

This makes it possible to mix two charge packets that are consecutive inthe horizontal direction as shown in FIG. 7B.

Each pair of transfer electrodes adjacent to each other may be suppliedwith the same voltage. However, it is desirable that each pair oftransfer electrodes be given a small voltage difference so as to producea transfer electric field in the charge transfer direction.

It is also possible to form a potential difference between each pair oftransfer electrodes by impurity doping in advance as in the case of thetwo-phase CCD. The potential difference should be smaller than a half ofthe amplitude of drive pulses.

FIGS. 8A-8C show a second exemplary operation of the case that the CCDimaging device outputs signal charges arranged in the horizontaldirection while mixing desired ones.

Four transfer electrodes adjacent to each other are considered a set andthe eight transfer electrodes 131-138 are driven in two phases. As shownin the bottom part of FIG. 8C, voltage differences α′, β′, γ′ areprovided between two, applied to two respective transfer electrodesadjacent to each other, of the horizontal transfer pulse signalsH11-H18.

This makes it possible to transfer four charge packets that areconsecutive in the horizontal direction in such a manner that they aremixed with each other as shown in FIG. 8B.

In the driving methods of FIGS. 7A-7C and FIGS. 8A-8C, the number ofsignal charge packets is halved by the mixing of signal charges adjacentto each other and the number of stages of the horizontal CCD register isalso halved. Therefore, with the same drive frequency, the timenecessary for transfer of all charged can be halved and the frame ratecan be doubled.

The above description is directed to the case of mixing charges that areoutput from two vertical CCD registers 110 adjacent to each other. Theinvention can be practiced in a similar manner even in the case ofmixing charges that are output from three or more vertical CCD registers110 adjacent to each other.

FIG. 9 is a schematic plan view of a horizontal CCD register of a CCDimaging device according to a second embodiment of the invention.

In this CCD imaging device, two horizontal CCD registers 220A and 220Bare provided for a plurality of vertical CCD registers 210. The twohorizontal CCD registers 220A and 220B alternately handle signal chargesthat are output from each pair of vertical CCD registers 210 adjacent toeach other and transfer signal charges parallel. The signal charges areoutput from a final gate section 240 to a charge detecting section.

The two horizontal CCD registers 220A and 220B have eight horizontaltransfer electrodes 231-238 that are independent of each otherelectrically. Eight kinds of horizontal transfer pulse signals H21-H28are applied to the respective transfer electrodes 231-238.

Also with this configuration, it is possible to output consecutivesignal charges while mixing desired ones by the same control as shown inFIGS. 7A-7C or 8A-8C.

The number of horizontal CCD registers is not limited to two. Theinvention can also be applied to a case that the number of horizontalCCD registers is three or more.

As described above, in the imaging device according to a first aspect ofthe invention having a single horizontal CCD register, the horizontalCCD register has horizontal transfer electrodes in such a manner thatfour transfer electrodes that are provided so as to correspond to eachvertical CCD register are independent of each other electrically.

Therefore, the horizontal transfer of signal charges can be performed bydriving the four transfer electrodes independently by arbitraryhorizontal transfer pulse signals. This makes it possible to outputsignal charges that are arranged consecutively in the horizontaldirection while mixing desired ones together as well as to increase theframe rate without increasing the drive frequency.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

In the imaging device according to a second aspect of the inventionhaving m horizontal CCD registers, the m horizontal CCD registers havehorizontal transfer electrodes in such a manner that all of transferelectrodes that are provided so as to correspond to each vertical CCDregister are independent of each other electrically.

Therefore, the horizontal transfer of signal charges can be performed bydriving the transfer electrodes independently by arbitrary horizontaltransfer pulse signals. This makes it possible to output signal chargesthat are arranged consecutively in the horizontal direction while mixingdesired ones together as well as to increase the frame rate withoutincreasing the drive frequency.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

In the driving method, according to the first aspect of the invention,of a CCD imaging device having a single horizontal CCD register, thehorizontal CCD register has horizontal transfer electrodes in such amanner that four transfer electrodes that are provided so as tocorrespond to each of the vertical CCD registers are independent of eachother electrically, and the four transfer electrodes are driven byindependent drive pulse signals.

Therefore, the horizontal transfer of signal charges can be performed bydriving the four transfer electrodes independently by arbitraryhorizontal transfer pulse signals. This makes it possible to outputsignal charges that are arranged consecutively in the horizontaldirection while mixing desired ones together as well as to increase theframe rate without increasing the drive frequency.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

In the driving method, according to the second aspect of the invention,of a CCD imaging device having m horizontal CCD registers, the mhorizontal CCD register have horizontal transfer electrodes in such amanner that all of transfer electrodes that are provided so as tocorrespond to each of the vertical CCD registers are independent of eachother electrically, and the transfer electrodes driven by independentdrive pulse signals.

Therefore, by driving the transfer electrodes independently by arbitraryhorizontal transfer pulse signals, signal charges that are arrangedconsecutively in the horizontal direction can be output while desiredones are mixed together. The frame rate can be increased withoutincreasing the drive frequency.

Further, by controlling horizontal transfer pulse signals in the samemanner as in the conventional method, the conventional two-phase drivingor the like can be realized, that is, an ordinary operation can also beperformed.

1. A CCD imaging device comprising: a plurality of photo-detectingportions that are arranged two-dimensionally; a plurality of verticalCCD registers to transfer, in a vertical direction, signal charges thatare output from the respective photo-detecting portions; and mhorizontal CCD registers to transfer, in a horizontal transferdirection, signal charges that are output from the respectivephoto-detecting portions, and m horizontal CCD registers to transfer, ina horizontal transfer direction, signal charges that have beentransferred by the vertical CCD registers, wherein the m horizontal CCDregisters has horizontal transfer electrodes such that a plurality ofelectrodes correspond to each of the vertical CCD registers, and apredetermined number of electrodes which are placed consecutively andmore than the plurality of electrodes that are provided so as tocorrespond to each of the vertical CCD registers are all independent ofeach other electrically and connected to different driving pulse lines.2. The CCD imaging device according to claim 1, wherein the transferelectrodes that are independent of each other electrically are dividedinto pairs of transfer electrodes, and wherein each pair of transferelectrodes are driven in phase in a state that they are given aprescribed voltage difference in such a manner that the potentialbecomes deeper in the horizontal transfer direction.
 3. The CCD imagingdevice according to claim 2, wherein transfer electrodes of the mhorizontal CCD registers that correspond to each set of n vertical CCDregisters adjacent to each other can be driven independently of eachother electrically, where n is greater than or equal to
 2. 4. A drivingmethod of a CCD imaging device including a plurality of photo-detectingportions that are arranged two-dimensionally, a plurality of verticalCCD registers to transfer, in a vertical direction, signal charges thatare output from the respective photo-detecting portions, and mhorizontal CCD registers to transfer, in a horizontal transferdirection, signal charges that have been transferred by the vertical CCDregisters, the method comprising: providing horizontal transferelectrodes via the m horizontal CCD registers such that a plurality ofelectrodes correspond to each of the vertical CCD registers, and apredetermined number of electrodes which are placed consecutively andmore than the plurality of electrodes that are provided so as tocorrespond to each of the vertical CCD registers are all independent ofeach other electrically and are driven by independent drive pulsesignals.
 5. The driving method according to claim 4, wherein thetransfer electrodes that are independent of each other electrically aredivided into pairs of transfer electrodes, and wherein each pair oftransfer electrodes are driven in phase in a state that they are given aprescribed voltage difference in such a manner that the potentialbecomes deeper in the horizontal transfer direction.
 6. The drivingmethod according to claim 5, wherein transfer electrodes of the mhorizontal CCD registers that correspond to each set of n vertical CCDregisters adjacent to each other can be driven independently of eachother electrically, where n is greater than or equal to
 2. 7. A CCDimaging device comprising: a plurality of photo-detecting portions thatare arranged two-dimensionally; a plurality of vertical CCD registers totransfer, in a vertical direction, signal charges that are output fromthe respective photo-detecting portions; and a horizontal CCD registerto transfer, in a horizontal transfer direction, signal charges thathave been transferred by the vertical CCD registers, wherein thehorizontal CCD register has horizontal transfer electrodes such that aplurality of electrodes correspond to each of the vertical CCDregisters, and a predetermined number of electrodes which are placedconsecutively and more than the plurality of electrodes that areprovided so as to correspond to each of the vertical CCD registers areall independent of each other electrically and each of the vertical CCDregisters are connected to different driving pulse lines.
 8. The CCDimaging device according to claim 7, wherein the vertical CCD registersare connected to four different driving pulse lines.
 9. The CCD imagingdevice according to claim 7, wherein pairs of the plurality ofelectrodes are impurity doped to form a potential difference betweeneach of the pairs of the plurality of electrodes.
 10. A driving methodof a CCD imaging device including a plurality of photo-detectingportions that are arranged two-dimensionally, a plurality of verticalCCD registers to transfer, in a vertical direction, signal charges thatare output from the respective photo-detecting portions, and horizontalCCD register to transfer, in a horizontal transfer direction, signalcharges that have been transferred by the vertical CCD registers, themethod comprising: providing horizontal transfer electrodes via thehorizontal CCD register such that a plurality of electrodes correspondto each of the vertical CCD registers; driving a predetermined number ofelectrodes by independent drive pulse signals, the predetermined numberof electrodes placed consecutively and more than the plurality ofelectrodes that are provided so as to correspond to each of the verticalCCD registers are all independent of each other electrically; andproducing a transfer electric field in a charge transfer direction viavoltage differences between pairs of transfer electrodes.
 11. Thedriving method of the CCD imaging device according to claim 10, furthercomprising: mixing first output signals arranged consecutively in ahorizontal direction with second output signals different from the firstoutput signals such that frame rate is increased and drive frequency isunaltered.
 12. The driving method of the CCD imaging device according toclaim 10, further comprising: impurity doping the pairs of transferelectrodes to form a potential difference between each of the pairs oftransfer electrodes.
 13. The driving method of the CCD imaging deviceaccording to claim 12, wherein the potential difference is smaller thanhalf of an amplitude of the drive pulse signals.
 14. The driving methodof the CCD imaging device according to claim 10, wherein thepredetermined number of electrodes are driven in four phases.